You can actually return it to Very even if it's been opened. All you need to do is quote the distance selling regulations on the return slip and they'll refund you.
I usually just mark it as faulty due to battery issues. If you go to Apple for support within 14 days of delivery, all they're gonna do is tell you to return it to the retailer anyway. Very really don't have a leg to stand on, as refusing the refund is illegal in the first place.